Sārasutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 1040

[1040] Bhikkhus, just as the footprints of whatever creatures walk upon the land all come to be encompassed within the elephant's footprint, and the elephant's footprint is declared the foremost of them, that is, on account of its great size — even so, bhikkhus, whatever steps lead to awakening, the faculty of wisdom (paññindriya) is declared the foremost of those steps, that is, for leading to awakening.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.